1. Field of the Invention
The present invention relates to crawler-type heavy equipment such as feller bunchers, backhoes, and the like that includes tracks or tires for transporting the apparatus from one location to the other and an upper that includes a cab, engine and hydraulics. The upper also supports a boom with a work implement at the free end of the boom such as a feller buncher, backhoe or the like. Even more particularly, the present invention relates to an improved heavy equipment apparatus with a tilting upper structure that features a ball support rigidly attached to the undercarriage deck wherein the upper rotatably connects to a flange assembly that tilts upon the rigid ball support.
2. General Background of the Invention
In the forestry industry, feller buncher devices are known that can work on the sides of hills, mountainsides, even though the terrain might be inclined a significant amount such as for example, between about 10.degree.-45.degree.. In such a situation, a piece of equipment must be rugged, able to cut and support trees, and at the same time maintain the operator in a substantially vertical position.
There are various commercially available heavy equipment designs that enable the heavy equipment to work on hills, mountainsides, and the like. Several of such heavy equipment undercarriages have been patented. The broad concept of a tilting arrangement between an undercarriage and a working upper is known in the art.
The Hashimoto U.S. Pat. No. 4,324,304 and the Crawford U.S. Pat. No. 4,326,571 disclose crawler-type undercarriages that can support an upper on a hill while maintaining the upper working portion of the apparatus in an upright position. The Hashimoto patent discloses a mobile carrier with laterally spaced apart traction means (such as spaced apart tracks), a work base adapted to be attached to a crown for rotation about an axis normal to the crown. The Hashimoto patent also provides a tilt mechanism joining the work base to the carrier for relative tilting movement between the base and the carrier.
The patent to Crawford discloses a mobile carrier wherein the tilt member is a ring provided with diagonally opposed holes adapted to receive pivots defining an orthogonal axis of the ring.